Source: streaming/protection/vo/ClearKeyKeySet.js

/**
 * The copyright in this software is being made available under the BSD License,
 * included below. This software may be subject to other third party and contributor
 * rights, including patent rights, and no such rights are granted under this license.
 *
 * Copyright (c) 2013, Dash Industry Forum.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *  * Redistributions of source code must retain the above copyright notice, this
 *  list of conditions and the following disclaimer.
 *  * Redistributions in binary form must reproduce the above copyright notice,
 *  this list of conditions and the following disclaimer in the documentation and/or
 *  other materials provided with the distribution.
 *  * Neither the name of Dash Industry Forum nor the names of its
 *  contributors may be used to endorse or promote products derived from this software
 *  without specific prior written permission.
 *
 *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS AS IS AND ANY
 *  EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 *  WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 *  IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
 *  INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 *  NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 *  PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 *  WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 *  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 *  POSSIBILITY OF SUCH DAMAGE.
 */

/**
 * @classdesc A collection of ClearKey encryption keys with an (optional) associated
 *  type
 * @ignore
 */
class ClearKeyKeySet {
    /**
     * @param {Array.<KeyPair>} keyPairs
     * @param {string} type the type of keys in this set.  One of either 'persistent'
     * or 'temporary'.  Can also be null or undefined.
     * @class
     * @ignore
     */
    constructor(keyPairs, type) {
        if (type && type !== 'persistent' && type !== 'temporary')
            throw new Error('Invalid ClearKey key set type!  Must be one of \'persistent\' or \'temporary\'');
        this.keyPairs = keyPairs;
        this.type = type;
    }

    /**
     * Convert this key set to its JSON Web Key (JWK) representation
     *
     * @return {ArrayBuffer} JWK object UTF-8 encoded as ArrayBuffer
     */
    toJWK() {
        var i;
        var numKeys = this.keyPairs.length;
        var jwk = {keys: []};

        for (i = 0; i < numKeys; i++) {
            var key = {
                kty: 'oct',
                alg: 'A128KW',
                kid: this.keyPairs[i].keyID,
                k: this.keyPairs[i].key
            };
            jwk.keys.push(key);
        }
        if (this.type) {
            jwk.type = this.type;
        }
        var jwkString = JSON.stringify(jwk);
        var len = jwkString.length;

        // Convert JSON string to ArrayBuffer
        var buf = new ArrayBuffer(len);
        var bView = new Uint8Array(buf);
        for (i = 0; i < len; i++)
            bView[i] = jwkString.charCodeAt(i);
        return buf;
    }
}

export default ClearKeyKeySet;